1. Field
The present disclosure relates to a system and a method of operating a printing system for parallel processing of a plurality of document jobs with a plurality of Raster Image Processors (RIPs) into a printer-ready format for printing of the document jobs.
2. Description of Related Art
Generating a print-ready documents to be printed by a printing system requires acquiring all the information (e.g., content, graphics, production specifications, etc.) required to view, process and output the desired document in an electronic format understandable by a print engine. Such systems range from those that are simple and modestly expensive, such as are well known to consumer users of personal computer systems, up to commercial printing systems that are capable of generating in the range of one thousand pages per minute in full color. All systems though have a high level objective of printing faster.
The process of converting information in the form of graphics, fonts and character placement information, and pictorial image content into a print-ready form, generally a raster image, possibly compressed or encoded in some way, is commonly known as Raster Image Processing (RIPping), and performed by what is called a Raster Image Processor (RIP). In any printing system, the speed is limited by the speed of the printer itself, (which is independent of the document complexity), and the speed of the RIP (which generally depends on the document, and may also depend on properties of the printer, such as its resolution, and its ability to support color), whichever is slower. The present application includes an embodiment that is directed at accelerating the RIP.
There are three general approaches that have been applied in the past for accomplishing the objective of printing faster. First, faster serial processing methods optimize the software and use faster and more expensive processors. Second, job parallel processing sends separate jobs to separate systems and then prints them on a common printer. Third, Portable Document Format (“PDF”) based page parallel systems convert the job to PDF, and then split the PDF file into pages which are converted to print-ready format on multiple independent processors, with the job being printed on a common printer.
Software optimization has its limitations and faster processors are also limited by currently available technology. Job parallel processing results in poor single job performance, unpredictable job time and reduced throughput when there is only one long job in the queue. The existing PDF-based solutions are slow due to their need to often convert from a different input language into PDF and then write the PDF file into an input spool disk. Page parallel processing has suffered from the inefficiencies of a throughput disadvantage because per job overhead occurs on a per page basis.
Accordingly, in the continuing need for improving efficiency and speed in printing systems, there is a need for a system which is not limited to mere job parallelism or page parallelism and that facilitates control and data flow of a print job to the printing system while splitting the print job(s) into a plurality of chunks or print job portions, each of which is processed independently and in parallel. The splitting operation is generally performed by a splitter in the printing system.
Small or short document jobs often present problems in printing systems. First, there is a per-job overhead at various points in the printing system and short document jobs are inefficiently processed because of this per-job overhead. When split, these short document jobs produce small chunks (i.e., print job portions)—they cannot produce chunks longer than the jobs themselves. These chunks appear as individual jobs to the RIPs. Each of these chunks or individual jobs have a per-job overhead. For example, two pages are generally processed by the RIP per second (for a job of appropriate complexity). With a one second overhead per job, document jobs less than 50 pages long run at least three percent slower than they would without the per-job overhead.
Another problem arises in continuous feed printing systems. To be efficient, these printing systems should be kept running for as long as possible. This is best suited to jobs having thousands of pages. The continuous feed printing systems are not efficient when processing small or short document jobs.
Applicants of the present disclosure have proposed a system and a method of operating a printing system for parallel processing of a plurality of small or short document jobs with a plurality of Raster Image Processors (RIPs) into a printer-ready format for printing of the document jobs that addresses at least the problems noted above.